This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Systemic Lupus Erythematosus-SLE is an autoimmune disease of uncertain etiology that affects predominantly women with a predilection for the African-American race. Development of nephritis is a prominent feature in SLE, contributing to morbidity and mortality. Although most patients with lupus have some renal involvement, only 15-30% have overt nephritis at the time of initial diagnosis. A further 15-30% of patients with SLE develop nephritis later in the course of their disease. The methods presently employed to screen for nephritis fail to detect early "silent" disease. Renal biopsy is the gold standard for the diagnosis of lupus nephritis. It is not suitable as a screening tool due to its invasive nature. Treatment options for nephritis are limited and associated with significant toxicity. Therapies are complicated by potentially life threatening adverse effects. If patients at risk of developing lupus nephritis could be identified early, this may allow for less toxic therapies to be employed which could potentially avert the development of overt renal disease. Our aim is to identify clinically useful markers of early sub-clinical disease. Such markers will also be helpful for the assessment of the efficacy of ongoing treatment. We will establish how selected biological markers and sensitive measurements of renal function relate to activity of nephritis as defined by renal biopsy in patients with SLE at the time of biopsy. In parallel we will conduct a longitudinal study examining the predictive value of the selected markers for the development of nephritis.